Code Regulations Applicable to Fuel Cells
Fuel Cell Systems are covered in Article 692 of the National Electrical Code (NEC). The Scope statement in 692.1 addresses “fuel cell power systems, which may be stand-alone or interactive with other electrical power production sources and may be with or without electrical energy storage such as batteries”.
The NEC Handbook adds “The rising demand for electrical power has led to the development of power sources that are viable alternatives to or can be interconnected with electric utility distribution systems. Article 692 is a new article that covers the installation of on-premises electrical supply systems where the power is derived from an emerging technology – fuel cells.
“The principle of operation is that direct current is generated through a chemical reaction in which fuel such as natural gas or LP-Gas is consumed. As opposed to internal combustion prime movers, the consumption of the fuel gas is via an electrochemical process rather than a combustion process. A power inverter converts the dc to ac. The installation requirements of this new article allow power derived from fuel cells to be safely delivered into residential and light commercial occupancies as the sole source of electrical power or as an integrated source with a utility or other power source”.
A summary of several of the key elements of Article 692, excerpted from the National Electrical Code and the National Electrical Code Handbook, are itemized below. Also included are convenient references to additional requirements that are located in other parts of the Code.
Article 692.3 indicates that wherever the requirements of other NEC Articles differ with Article 692, the requirements of Article 692 shall apply.
Article 692.3 also indicates that if the fuel cell system is operated in parallel with a primary source or sources of electricity, the requirements of NEC 705.14, 705.16, 705.32 and 705.43 shall apply.
Article 692.14 indicates that Articles 225.31 and 225.33 through 225.40 shall apply to the fuel cell source disconnecting means. It is not required that the disconnecting means be suitable as service equipment.
Article 692.41 (A) references Article 250.30 for the grounding and bonding of stand-alone fuel cell systems.
Article 692.45 references Article 250.122 regarding the size of the equipment grounding conductor.
Article 692.47 references Article 250.118 regarding the connection of any supplemental grounding electrode required by the manufacturer.
Article 692.59 requires a transfer switch in non-grid-interactive systems that use utility grid backup. When the utility service conductors of the structure are connected to the transfer switch, the switch shall comply with Part V of Article 230.
The following National Electrical Code requirements make reference to the listing (third party certification) requirements of fuel cell systems.
Article 692.6 requires that fuel cell systems be evaluated and listed for their intended application prior to installation.
Article 692.60 requires that only fuel cell systems listed and identified as interactive (operating in parallel with and able to deliver power to an electrical production and distribution network) shall be permitted in interactive systems.